I would just go with regular very porous dry rock, that's what I did this time on my 75, and I am so happy on not having any pests, aiptasia, bubble algae etc are a complete pain and nearly impossible to erradicate.
Also keep in mind you do not need to follow the common 1-1.5 lbs per gallon, IMO that is only if you use bad quality rock, good porous light rock does not require quite as much to provide filtration, aditionally you can get away with a very minimalistic look and put some Marine Pure ceramic media, a single block is sufficient for up to 300 gallons or more, looking at Eckolancer's tank, I am pretty sure that is what he is using, as the rock is very minimal and would likely not provide sufficient filtration by itself.
Just keep in mind that fish like rock because of the hiding spaces it provide, but if you intend to have tons of corals they can hide there just as well, just make sure you have enough biological filtration.